Long-term results of a prospective, Phase II study of long-term androgen ablation, pelvic radiotherapy, brachytherapy boost, and adjuvant docetaxel in patients with high-risk prostate cancer

Continuous liquid interface production of 3D printed drug-loaded spacers to improve prostate cancer brachytherapy treatment

Brachytherapy, which is the placement of radioactive seeds directly into tissue such as the prostate, is an important curative treatment for prostate cancer. By delivering a high dose of radiation from within the prostate gland, brachytherapy is an effective method of killing prostate cancer cells while limiting radiation dose to normal tissue. The main shortcomings of this treatment are: less efficacy against high grade tumor cells, acute urinary retention, and sub-acute urinary frequency and urgency. One strategy to improve brachytherapy is to incorporate therapeutics into brachytherapy. Drugs, such as docetaxel, can improve therapeutic efficacy, and dexamethasone is known to decrease urinary side effects. However, both therapeutics have high systemic side effects. To overcome this challenge, we hypothesized that we can incorporate therapeutics into the inert polymer spacers that are used to correctly space brachytherapy seeds during brachytherapy to enable local drug delivery. To accomplish this, we engineered 3D printed drug-loaded brachytherapy spacers using continuous liquid interface production (CLIP) with different surface patterns to control drug release. These devices have the same physical size as existing spacers, allowing them to easily replace commercial spacers. We examined these drug-loaded spacers using docetaxel and dexamethasone as model drugs in a murine model of prostate cancer. We found that drug-loaded spacers led to higher therapeutic efficacy for brachytherapy, and there was no discernable systemic toxicity from the drug-loaded spacers. STATEMENT OF SIGNIFICANCE: There has been high interest in the application of 3D printing to engineer novel medical devices. However, such efforts have been limited by the lack of technologies that can fabricate devices suitable for real world medical applications. In this study, we demonstrate a unique application for 3D printing to enhance brachytherapy for cancer treatment. We engineered drug-loaded brachytherapy spacers that can be fabricated using Continuous Liquid Interface Production (CLIP) 3D printing, allowing tunable printing of drug-loaded devices, and implanted intraoperatively with brachytherapy seeds. In combined chemotherapy and brachytherapy we are able to achieve greater therapeutic efficacy through local drug delivery and without systemic toxicities. We believe our work will facilitate further investigation in medical applications of 3D printing.

The Impact of Pelvic Nodal Radiotherapy on Hematologic Toxicity: A Systematic Review with Focus on Leukopenia, Lymphopenia and Future Perspectives in Prostate Cancer Treatment

INTRODUCTION

Hematologic toxicity (HT), particularly leukopenia, is a common side-effect of oncologic treatments for pelvic malignancies. Pelvic nodal radiotherapy (PNRT) has been associated with HT development mainly through incidental bone marrow (BM) irradiation; however, several questions remain about the clinical impact of radiotherapy-related HT. Herein, we perform a systematic review of the available evidence on PNRT and HT.

MATERIALS AND METHODS

A comprehensive systematic literature search was performed through EMBASE. Hand searching and clinicaltrials.gov were also used.

RESULTS

While BM-related dose-volume parameters and BM-sparing techniques have been more thoroughly investigated in pelvic malignancies such as cervical, anal, and rectal cancers, the importance of BM as an organ-at-risk has received less attention in prostate cancer treatment.

CONCLUSIONS

We examined the available evidence regarding the impact of PNRT on HT, with a focus on prostate cancer treatment. We suggest that BM should be regarded as an organ-at-risk for patients undergoing PNRT.

Brachytherapy boost (BT-boost) or stereotactic body radiation therapy boost (SBRT-boost) for high-risk prostate cancer (HR-PCa)

Systematic review for the treatment of high-risk prostate cancer (HR-PCa, D'Amico classification risk system) with external body radiation therapy (EBRT)+brachytherapy-boost (BT-boost) or with EBRT+stereotactic body RT-boost (SBRT-boost). In March 2020, 391 English citations on PubMed matched with search terms "high risk prostate cancer boost". Respectively 9 and 48 prospective and retrospective studies were on BT-boost and 7 retrospective studies were on SBRT-boost. Two SBRT-boost trials were prospective. Only one study (ASCENDE-RT) directly compared the gold standard treatment [dose-escalation (DE)-EBRT+androgen deprivation treatment (ADT)] versus EBRT+ADT+BT-boost. Biochemical control rates at 9 years were 83% in the experimental arm versus 63% in the standard arm. Cumulative incidence of late grade 3 urinary toxicity in the experimental arm and in the standard arm was respectively 18% and 5%. Two recent studies with HR-PCa (National Cancer Database) demonstrated better overall survival with BT-boost (low dose rate LDR or high dose rate HDR) compared with DE-EBRT. These recent findings demonstrate the superiority of EBRT+BT-boost+ADT versus DE-EBRT+ADT for HR-PCa. It seems that EBRT+BT-boost+ADT could now be considered as a gold standard treatment for HR-PCa. HDR or LDR are options. SBRT-boost represents an attractive alternative, but the absence of randomised trials does not allow us to conclude for HR-PCa. Prospective randomised international phase III trials or meta-analyses could improve the level of evidence of SBRT-boost for HR-PCa.

A Phase II Study Evaluating Bone Marrow-Sparing, Image-guided Pelvic Intensity-Modulated Radiotherapy (IMRT) With Cesium-131 Brachytherapy Boost, Adjuvant Chemotherapy, and Long-Term Hormonal Ablation in Patients With High Risk, Nonmetastatic Prostate Cancer

PURPOSE/OBJECTIVE(S)

Management of localized high-risk prostate cancer remains challenging. At our institution we performed a prospective phase II study of 2 years of androgen deprivation therapy (ADT), pelvic radiation, Cesium (Cs)-131 brachytherapy boost, and adjuvant docetaxel in high risk, localized prostate cancer with a primary endpoint of 3-year disease-free survival.

MATERIALS/METHODS

Acute/chronic hematologic, gastrointestinal (GI) and genitourinary (GU) toxicities were scored based on the CTCAE v3.0/RTOG-EORTC criteria, respectively. Actuarial biochemical recurrence free survival (bRFS), bRFSdisease free survival (DFS) and overall survival (OS) were calculated. Patients had a median age of 62 years (range, 45 to 82), median Gleason score 8 (74% Gleason 8-10), median PSA of 11.2 (range, 2.8 to 96), and 47% cT2-T3a stage disease. Androgen deprivation was given for 2 years, 45 Gy whole-pelvis IMRT was followed by an 85 Gy Cs-131 boost to the prostate gland, and adjuvant docetaxel was given for 4 cycles.

RESULTS

In total 38 patients enrolled from 2006 to 2014, with 82% completing protocol specified treatment, and 84.2% completing 4 cycles of docetaxel. Median follow-up for the entire and alive cohorts were 44 months and 58 months (range, 3.4 to 118), respectively. Acute grade ≥2 GI and GU toxicity rates were 18.4% and 23.7%, respectively. Chronic grade ≥2 GI and GU toxicity rates were 2.6% and 2.6%, respectively. Twelve patients (31.6%) developed grade 4 hematologic toxicity, with no grade 5 toxicity. The 5-year DFS, bRFS and OS rates were 74.1%, 86.0%, and 80.3%, respectively.

CONCLUSIONS

This aggressive pilot multimodal approach appears to be safe and well-tolerated, providing disease control in a significant proportion of patients with particularly high-risk prostate cancer.

Phase I trial of weekly docetaxel, total androgen blockade, and image-guided intensity-modulated radiotherapy for localized high-risk prostate adenocarcinoma

BACKGROUND

This was a phase I study to find the maximum tolerable dose (MTD) of weekly docetaxel combined with high-dose intensity-modulated radiotherapy (IMRT) and androgen deprivation therapy (ADT).

PATIENTS AND METHODS

Men with localized high-risk prostate cancer (HRPC) were treated with weekly docetaxel at 10 to 30 mg/m(2) concurrent with IMRT of 77.4 Gy to the prostate and 45 Gy to the seminal vesicles. ADT consisted of a gonadotropin-releasing hormone agonist (GnRHa) and bicalutamide beginning 2 months before and during chemoradiation. GnRHa was continued for 24 months.

RESULTS

Nineteen patients were enrolled. No dose-limiting toxicity (DLT) was seen with docetaxel doses up to 25 mg/m(2). At the 30 mg/m(2) level, 2 of 4 patients experienced DLTs of both grade 3 fatigue and dyspepsia. At 41 months' median follow-up, 2 patients had died--1 from metastatic prostate cancer and the other from heart failure. Two other patients experienced biochemical failure. One patient with bladder invasion at diagnosis experienced late grade 2 urinary hesitancy 9 months after completion of radiotherapy, requiring short-term intermittent catheterization. All patients had erectile dysfunction, but no late toxicities worse than grade 2 were identified.

CONCLUSION

Weekly docetaxel may be combined with high-dose IMRT and long-term ADT up to a MTD of 25 mg/m(2). Acute toxicities and long-term side effects of this regimen were acceptable. Future studies evaluating the efficacy of docetaxel, ADT, and IMRT for localized HRPC should use a weekly dose of 25 mg/m(2) when limiting the irradiated volume to the prostate and seminal vesicles.

Outcomes of Gleason Score ≤ 8 among high risk prostate cancer treated with 125I low dose rate brachytherapy based multimodal therapy

PURPOSE

To investigate the role of low dose rate (LDR) brachytherapy-based multimodal therapy in high-risk prostate cancer (PCa) and analyze its optimal indications.

MATERIALS AND METHODS

We reviewed the records of 50 high-risk PCa patients [clinical stage ≥ T2c, prostate-specific antigen (PSA) >20 ng/mL, or biopsy Gleason score ≥ 8] who had undergone 125I LDR brachytherapy since April 2007. We excluded those with a follow-up period <3 years. Biochemical recurrence (BCR) followed the Phoenix definition. BCR-free survival rates were compared between the patients with Gleason score ≥ 9 and Gleason score ≤ 8.

RESULTS

The mean initial PSA was 22.1 ng/mL, and mean D90 was 244.3 Gy. During a median follow- up of 39.2 months, biochemical control was obtained in 72% (36/50) of the total patients; The estimated 3-year BCR-free survival was 92% for the patients with biopsy Gleason scores ≤ 8, and 40% for those with Gleason scores ≥ 9 (p<0.001). In Cox multivariate analysis, only Gleason score ≥ 9 was observed to be significantly associated with BCR (p=0.021). Acute and late grade ≥ 3 toxicities were observed in 20% (10/50) and 36% (18/50) patients, respectively.

CONCLUSION

Our results showed that 125I LDR brachytherapy-based multimodal therapy in high-risk PCa produced encouraging relatively long-term results among the Asian population, especially in patients with Gleason score ≤ 8. Despite small number of subjects, biopsy Gleason score ≥ 9 was a significant predictor of BCR among high risk PCa patients after brachytherapy.

Current role of neoadjuvant and adjuvant systemic therapy for high-risk localized prostate cancer

PURPOSE OF REVIEW

Although most men are diagnosed with readily curable localized prostate cancer, those with high-risk features face a significant mortality risk. Androgen deprivation therapy (ADT) is a standard adjunct to radiotherapy for high-risk prostate cancer, but its role around prostatectomy has not been as clearly defined, and concerns over cardiovascular toxicity have led to decreasing use. The use of chemotherapy for localized disease remains experimental. We review the most recently published trials of neoadjuvant or adjuvant systemic therapy for prostate cancer.

RECENT FINDINGS

The optimal duration of ADT with higher dose modern radiation techniques is under active investigation, but current data support the use of longer duration as standard. Prostate-specific antigen (PSA) and MRI changes may be useful in future studies optimizing duration of neoadjuvant ADT. Two years of combined ADT after prostatectomy is associated with a lower risk of disease recurrence and better prostate cancer specific mortality than predicted. Persistence of intraprostatic androgens during neoadjuvant ADT may contribute to resistance.

SUMMARY

Androgen deprivation added to definitive radiation or surgery improves outcomes for high-risk prostate cancer, although the role of chemotherapy remains undefined. Molecular classification is needed to improve risk stratification.

Toxicity in patients receiving adjuvant docetaxel + hormonal treatment after radical radiotherapy for intermediate or high-risk prostate cancer: a preplanned safety report of the SPCG-13 trial

BACKGROUND

Radical radiotherapy (RT) combined with androgen deprivation therapy is currently the standard treatment for elderly patients with localized intermediate- or high-risk prostate cancer (PC). To increase the recurrence-free and overall survival, we conducted an adjuvant, randomized trial using docetaxel (T) in PC patients (Scandinavian Prostate Cancer Group trial 13).

METHODS

The inclusion criteria are the following: men >18 and ≤75 years of age, WHO/ECOG performance status 0--1, histologically proven PC within 12 months before randomization and one of the following: T2, Gleason 7 (4+3), PSA >10; T2, Gleason 8--10, any PSA; or any T3 tumors. Neoadjuvant/adjuvant hormone therapy is mandatory for all patients. The patients were randomized to receive six cycles of T (75 mgm(-2) d 1. cycle 21 d) or no docetaxel after radical RT (with a minimum tumor dose of 74 Gy). This study identifier number is NTC 006653848 (http://www.clinicaltrials.org).

RESULTS

In this preplanned safety analysis of 100 patients, T treatment induced grade (G) 3 adverse events (AEs) in 15 patients (30%) and G4 AEs in 30 patients (60%), mainly due to bone marrow toxicity. Neutropenia G3--4 was observed in 72% of the patients, febrile neutropenia was found in 24% of patients, neutropenic infection in 10% of patients and G3 infection without neutropenia in 4% of patients. Nonhematological G3 AEs were rare: anorexia, diarrhea, mucositis, nausea, pain (1 patient each) and fatigue (5). Other severe serious AEs related to T were pulmonary embolism and renal failure. However, only three patients discontinued T before completing the planned six cycles. No deaths had occurred. No patients in the control arm experienced G3--4 toxicities at 12 weeks after the randomization.

CONCLUSIONS

Adjuvant docetaxel chemotherapy after radiotherapy has a higher frequency of neutropenia than previous studies on patients with metastatic disease. Otherwise, the treatment was quite well tolerated.